The New Zealand international had a year left to run on his current contract and was intent on extending his stay with the club that gave him his start in professional soccer.
"I could have looked at other options, but honestly there is nowhere else I wanted to be," Sigmund said.
"My family is here and I love this club so why move if they want me to stay?
"They have looked after me with an improved contract and it being for three years gives me security for the family."
The combative 31-year-old joined the club in 2008 on a one-year deal and has made 91 appearances since then.
Phoenix head coach Ricki Herbert was happy that Sigmund, capped 18 times at international level, was prolonging his stay at the club.
"Ben has had a couple of excellent seasons and played a leading role in us reaching the playoffs in the last three years," Herbert said.